DE102006030671B4 - Breaker short-O combination - Google Patents

Abstract

Breaker, In particular, multiphase circuit breaker for low voltage, with an opening-closing apparatus (16) for each phase (L1, L2, L3) and at least one detection unit (20) for one Residual current (77) in at least one phase (L1, L2, L3) one to protected electrical system (40), wherein the circuit breaker (10) at least formed on the load side (LS) power connection rails (12) are characterized in that at least on the power supply rails (12) the load side (LS) of the circuit breaker (10) a short-circuiter (30) is arranged with one of the detection unit (20). fault current detected a short circuit between the power connection rails (12) can be produced.

Description

The The invention relates to an electrical circuit breaker, in particular a circuit breaker for Low voltage.

The Breaking and the turn-off time of a circuit breaker when a fault current occurs, especially when an overcurrent, a short circuit occurs or an arc fault, hang from different parameters. The switch-off process continues together from the trigger time, the own time and the off time. The trigger time is the time from the onset the trigger causing size to Initiating the triggering process, for example, the unlatching of a switching mechanism. It closes the proper time of the switch, due to the dynamic processes of the moving and opening Contacts of the switch are conditional. With a switch for the higher power range (Rated current up to 100 kA) is expected with a turn-off time of about 50 msec.

in the Case of occurrence of an arc fault in an electrical system can cause serious personal injury and / or property damage, which applies preferably to limit. To limit such damages are various measures have been proposed, of which the shutdown (deleting) of the arc fault in shorter Time when the switch-off time of the supply switch is the optimal solution.

As is known, short-circuiters are used to switch off arcing faults in electrical systems. For such an arrangement for extinguishing an arc, different detection systems for physical effects of the burning arc (light, sound, pressure) can be used. A proven system is based on the optical detection of an arc ( EP 0575 932 B1 ). To switch off the arc different Kurzschließeranordnungen be proposed, for example, the use of a pyrotechnically driven short circuiter ( EP 1052 665 B1 or WO 200062320 A1 ); by a short circuit to be switched via thyristors ( DE 4438593 A1 ) or the use of a vacuum interrupter ( DE 4404074 A1 ). With such short-circuiting devices, a short circuit is created between the phases of the network between which the arc burns, so that the arc can be extinguished in less than 3 msec. The advantage of an arc detection and extinguishing system is obvious.

To Switching the short-circuiter is still flowing a short-circuit current coming from the series-connected feed switch (after its off time) is switched off, causing the faulty electrical Plant is eventually disconnected from the grid. An arc detection and extinguishing system Accordingly, from detection means, a short-circuiter and associated electronic switching means.

at Installation of a 'conventional' arc detection and extinguishing system becomes a short circuiter the circuit breaker connected in parallel, so that the busbar terminals of the circuit breaker further busbar elements are arranged, at the ends of the Short circuiter positioned becomes. The quality, in particular, the cross section of the busbar elements must those Busbars comply with those of the circuit breaker and the electrical system are powered. This means that for the - in itself 'passively present' - short-circuiter, the only for the rare emergency of a fault arc is provided, operated a considerable amount of material must become. Therefore, the length becomes the for the connection of the short circuiter as possible to be used busbars short-listed, so the short-circuiter in relative close proximity to the circuit breaker.

The Busbars carrying the load current and the circuit breaker heat by the current heat and get an increased operating temperature. The raised Operating temperature is over the highly conductive Connecting rails also with the short circuiter. However, short circuiters have, in particular those which are designed as pyrotechnic short-circuiting, a thermal load limit. For example, a pyrotechnic Generator so far not over a constant temperature of 85 ° C operate. To exclude a thermal load is when installing pyrotechnic short-circuiting on the connection rails Heat sink clamped. Of the Use of cooling elements is also an additional one Cost of materials.

There is known a circuit breaker in a low-voltage distribution with a bypass switch ( DE 41 10 335 A1 ). The bypass switch is located on the load side of the low-voltage distribution and serves as a short-circuiter that closes when a short-circuit occurs in a load.

It is also known a circuit breaker, are mounted on the load side of power supply rails, which are connected to a busbar ( DE 196 43 607 A1 ).

The invention is therefore based on the object at a circuit breaker, at least on the load side power connection rails before Hand are measures to provide, which is associated with a reduction of material costs and allows for over the normal function of the circuit breaker accelerated shutdown of a short circuit.

The The object is achieved by the characterizing features of the independent claim, while the dependent claims advantageous developments of the invention can be seen.

Of the The core of the invention is that at least on the load side of the circuit breaker a short-circuiter is arranged on the power connection rails for the production a short circuit between the busbars in one of a Fault current detection unit detected fault current. As a fault current a short circuit or a burning arc fault can be detected and switched off become. A short-circuiter may also be formed on the network side of the circuit breaker.

to Arrangement of the short-circuiter should fasteners for easy, quick and detachable fastening to be available. For example, a tension lever system may be used be, in which - without Screwing - the Earthing is fixed with a firm seat on the power connection rails. Alternatively, it can also be provided that on the connection busbars of the circuit breaker threaded bolts are arranged, with connection points in the short circuiter correspond, for example, where there are holes that over the Threaded bolts are pushed. The attachment is then done by screws (possibly with washers).

It understands that it is preferable to the presence of the short closer also an arc detection system in the electrical system to assemble. In a 'simplified execution However, the detection of a fault current can be based solely on the use a short-circuit detector (current transformer and short-circuit release) in the circuit breaker limited stay. It should be It will be clear to the person skilled in the art that this design only the lower stage a system of protection against system disturbances.

Of the typical use of a short-circuiter is the arrangement on be the load side of the circuit breaker. Thus, the short-circuiter occurs between circuit breaker and the underlying electrical system (for example, or distribution station, transformer station, electric motor) and separates the Plant in a short circuit from the network.

Indeed can be a short circuiter also be introduced on the network side of the short-circuiter. For an 'extensive protection situation' can thus also two short circuiters be present: one in front and one behind the circuit breaker. Of the Use on the mains side of the circuit breaker has the advantage itself, that also the entire connection area (transformer, cables, rails) 'in front of the circuit breaker' in the surveillance zone of the short circuiter lies. When an arc occurs in the connection area deletes an activated short-circuiter the fault arc and the upstream, higher-level feed-in protection switch falls the 'task', the existing Disconnect short circuit. It can be used to optimize the system as well be provided that in the connection area an arc fault detection unit is built over a switching signal is transmitted to the short-circuiter.

The inventive arrangement allows that the circuit breaker is fully valid can be operated independently whether the short-circuiter is in function (armed) or disabled (but not short-circuited).

It can Fastening means and / or an insertion shaft may be provided for the short-circuiter. The short circuiter should be at any time from the outside accessible be. An installed short-circuiter should be lockable for security reasons. Preferably, a flap or a lid may be present.

Farther it is proposed, funds for to provide the seal of an installed short-circuiter. Changing a short circuiter then only after destruction the sealing done. The short-circuiter can thus be protected against unauthorized removal to back up.

Further advantageous embodiments of the inventions are shown as follows:
There are electrical contact means, which are suitable for receiving arranged on the short-circuiting electrical counter contact means. About the contact means of the short-circuiting is controlled by the circuit breaker, or by an electronic module formed in the circuit breaker. The electrical contact means (such as plugs and sockets) are automatically coupled when inserting the short-circuiting in the insertion shaft.

About the Contact means are electrical performance data, working variables, setting variables and / or triggering signals between circuit breaker and short circuiter can be transmitted.

Of the Circuit breaker can be a barrier against the reconnection of the Have circuit breaker, which after triggering the switching function in the short-circuiting in function occurs.

As In the introduction are addressed different types and types of short circuiters known. One for the respective purpose well suited short circuiter will be the skilled person respectively determine and select can. Preferably, a pyrotechnically driven short circuiter is recommended. To whose drive can provide a nitrocellulose-based chemistry be. The connection rails in the short-circuiter form a sandwich-like Package. The pyrotechnic drive drives a metallic bolt through the stack of connecting rails, allowing the phases inside be mechanically contacted with each other of less than 1 msec and a short circuit is generated. In a situation where the short circuit is present as a burning arc fault, the energy is removed from the arc and it goes out.

Of the Earthing should short circuit at least two phases of the power connection. It will In expert circles also discussed, the short-circuiter for contacting at least to establish a phase of the power connection to ground (established for switching to PE). Both embodiments can be used.

Of the Circuit breaker is - as usual - with a detection electronics for detecting a fault current on the load side in at least a phase equipped. For this purpose, a current transformer available be for detecting a load-side fault current in a the phases is created. When crossing a predetermined threshold of current gradient and / or current a corresponding signal over the contact means for activating the short-circuiter transmitted.

Of the Operating state of the short-circuiter is from an energy store (for example from a capacitor bank) upright, whose stored energy for actuation (ignition) of the Earthing drive sufficient. The charge of the energy storage should be permanent be. Therefore, it is advantageous if the energy storage a permanent power supply is available. This should be independent of Be mains, on which the electrical system and the circuit breaker lie. The power supply may be battery-powered or off a supply from a parallel electrical network. At a Battery-supported variant have to worry about that be worn, that the battery is always full charge has what is easiest by means of automatic charge monitoring is feasible.

So long there is a short circuit in the short circuiter, the restarting of the circuit breaker should be prevented. Only when the short circuit is canceled, resulting in the replacement of the short closer against a functioning short-circuiter or by renewal dysfunctional Parts or even by non-replacement, should be a reconnect possible be. This achieves a high level of system and personal protection.

Also if there is no lock against reconnection, there is a Advantage ago, because when turning on the circuit breaker while on the short circuit of the short circuiter is switched, but the electrical system remains de-energized.

Of the Use of the circuit breaker according to the invention is practically common in all cabinets of electrical systems possible. The circuit breaker-short-circuiter combination is a compact unit. An additional space requirement exists Not. For such reasons can the circuit breaker of the invention be replaced with existing switching systems in a retrofit process.

The Conductors and busbars of circuit breakers and short circuiters should for one Short-circuit current from over 100 kA over be designed for a period of up to 500 ms. With this requirement It is under certain embodiments of the electrical system possible, for the Plant the criteria for their Reduce short circuit strength. So far, it was assumed that busbars, rail supports and further current-carrying Parts of an electrical system for a maximum expected Short-circuit current upgraded should be. When using the circuit breaker-short-circuiter combination the short circuiter switches the electrical system within 2 msec. The short-circuit load the system is thus minimized. An otherwise existing requirement to an electrical system for maximum short-circuit resistance does not have to be fully fulfilled become. This goes without saying for the Plant operators economic benefits.

When Another advantage is highlighted that the switching function of Circuit breaker is shortened. The full short-circuit current occurring directly in the circuit breaker is from the short-circuit trigger detected. Magnetic short-circuit release refer the triggering energy from the source of interference itself and 'react' according to the Height of Current. Unlike a metallic short circuit sets arc a muted Short circuit because the arc fault voltage over a finite ohmic resistance drops.

As previously stated, circuit breakers have a turn-off time of up to 50 msec. Circuit breakers are designed to be loaded with full short-circuit current during this time you can. The stronger short-circuit current leads to an accelerated reaction of the short-circuiter, and thus to a shortening of the switch-off time of the circuit breaker. It comes almost to a lowering of the voltage level for short circuit. The load duration is shortened. It comes to a relief of the circuit breaker for maximum switching loads.

Further Details and advantages of the invention will become apparent from the following explained in the figures Embodiments. Show it

1A and 1B : a perspective view of circuit breaker and short circuiter,

2 : A schematic circuit arrangement of a short circuit breaker combination and

3 : a perspective view after 2 ,

The illustrations in the figures show one as a circuit breaker 10 trained circuit breaker, in front of an electrical consumer 40 in a three-phase (L1, L2, L3) network. The circuit breaker has at least one detection unit (short-circuit release) and an overload release. The latter can be designed as a bimetallic trigger. Overload releases operate with a time delay when a high, pre-settable current value occurs and cause the contacts of the circuit breaker to open via the switch lock 16 , The envisaged detection unit 20 is available as an electronic unit by current collection means 21 is controlled. As current detection means current transformer, such as Hall sensors can be provided.

The Breaker short-O combination is that at least one attachment point, a short-circuiter available is.

According to 1B On the load side LS of the circuit breaker is the space in which a short-circuiting device is installed. There are the busbars 12 each phase L1, L2, L3 accessible and with funds 32 (here threaded bolt) for releasable installation (contacting, fastening, connecting, screwing) of the short-circuiter 30 Mistake. With the short-circuiter 30 can be the network-side busbars 12 (Phases L1, L2, L3) short-circuit each other.

In the arrangement according to 1 the circuit breaker is fed from below (mains side); in 2 In contrast, the feed side (schematically) indicated above.

To attach a short-circuiter is an insertion shaft 14 . 14 ' available. The housing of the circuit breaker is - according to figure representation - formed with an integrated insertion shaft. The short-circuiting device is designed in terms of design and geometry so that it is adapted to the housing of the circuit breaker, or the insertion shaft. It can be dispensed with a separate housing design of the circuit breaker, if an insertion shaft is not considered necessary. It must be provided that the short-circuiter alone 30 in any form attachable to the power supply rails (flanges) is.

On the front of the circuit breaker there are adjusting buttons, the usual may be present in such switches. For example, there can be the short circuit sizes to the Buttons set become.

The Assembly (insertion and installation) of the short-circuiter is indicated by arrows in the figures.

Preferably, the circuit breaker for mounting a short-circuiter 30 be designed both on the network side NS of the circuit breaker as on the load side LS of the circuit breaker. It should be noted that in the 1 and 3 the load side LS above and in 2 the load side LS is below.

In 1A is in the short circuiter a pyrotechnic generator with reference numerals 35 indicated. In the housing part of the short-circuiting are connection plugs and lines for the / the pyrotechnic gas generator / s (reference numerals 35 ) protected. The connection plugs are protected against unintentional removal. The connection rails 34 of the short circuiter 30 in which holes 32 ' are present at the attachment points with the busbars 12 and or 12 ' contacted and thus connected in parallel. The short circuiter 30 occurs when a fault current occurs, especially in the event of a short circuit in the electrical system 40 triggered.

The circuit diagram of the circuit breaker-short-circuiter combination is shown schematically in FIG 2 shown.

A short circuit is from the electronic detection unit 20 of the circuit breaker (short-circuit release), but not detected by the overload release. The core of the registration unit 20 is a current transformer 21 ,

The detection unit is set to predetermined values (threshold) of current slope and current. When exceeding a predetermined Threshold, for example when an arc occurs 77 sends the registration unit 20 a signal (S1, S2) to both the short-circuiter 30 as well as the switch lock with a 'command' S2 to open the contacts of the circuit breaker 10 ,

Now runs the switch-off of the circuit breaker, at the end of which the short circuit leading short circuiters (and behind the electrical system 40 ) is disconnected from the network.

Electrical contact means are denoted by reference numerals 24 ' . 24 '' characterized. They are for receiving arranged on the short-circuiting electrical counter contact means 36 ' . 36 '' educated. The electrical contact means (such as plugs and sockets) are automatically coupled during assembly of the short circuiter.

After switching the short-circuiter 30 is intended to put a lock against restarting the circuit breaker in function. The blocking function can be mechanical or electromechanical.

to Recommissioning of the electrical system should be done by the short circuiter a new functional Earthing In this case, the lock function is also canceled. Of the Circuit breaker is for equipped with multiple switching of a short-circuit current, so that this continues to operate in the event of multiple occurrence of a fault current can be.

Not shown in detail is a detection unit for an arc fault. Reference has already been made to such a recording system ( EP 0575 932 B1 ). In this case, an optical unit with optical waveguides is used, which is coupled to a parallel current detection (for example via Hall sensors). Upon the occurrence of the flash of light of the arc fault and with the rapid increase of the fault current originating from the arc, a switching signal S3 is given by the arc fault detection unit to the short-circuiter, which is thus caused to act.

The 3 shows again a perspective view 2 with a compartment shown schematically 14 ' on the load side LS (top) and a compartment 14 on the mains side NS (below) for installation of the short circuiter 35 ,

10

breakers

12

load side Power supply rails

12 '

network side Power supply rails

14 14 '

insertion shaft; compartment

16

switch lock

20

electronic shutter

21

current detection (Power converter)

24 '24' '

plug

30

Earthing

32 32 '

attachment points (Threaded bolts, nuts)

34

Connecting bars

35

pyrotechnic generator

36 '36' '

plug

37

power supply external or battery

40

Consumer, elec. investment

77

arc

S1

trigger signal to short circuiter

S2

trigger signal to circuit breaker

S3

signal from current detection on network side

L1 L2 L3

current phases

NS

network side

LS

Last page

Claims (13)

Circuit breaker, in particular multi-phase low-voltage circuit-breaker, having an opening-closing apparatus ( 16 ) for each phase (L1, L2, L3) and at least one detection unit ( 20 ) for a fault current ( 77 ) in at least one phase (L1, L2, L3) of an electrical system to be protected ( 40 ), with the circuit breaker ( 10 ) at least on the load side (LS) power connection rails ( 12 ) are formed, characterized in that at least on the power supply rails ( 12 ) of the load side (LS) of the circuit breaker ( 10 ) a short circuiter ( 30 ) is arranged with one of the detection unit ( 20 ) detected fault current a short circuit between the power supply rails ( 12 ) can be produced. Circuit breaker according to claim 1, characterized in that also on the network side (NS) of the circuit breaker ( 10 ) Power connection rails ( 12 ' ) are formed, on which a short-circuiter ( 30 ) is arranged. Circuit breaker according to claim 1 or 2, characterized by establishing a short circuit between the power supply rails ( 12 . 12 ' ) at one of the registration unit ( 20 ) recorded arc ( 77 ). Circuit breaker according to claim 1 or 2, characterized by establishing a short circuit between the power supply rails ( 12 . 12 ' ) at one of the registration unit ( 20 ) detected short-circuit current. Circuit breaker according to one of the preceding claims, characterized in that the short circuiter ( 30 ) is detachably arranged. Circuit breaker according to one of the preceding claims, characterized in that for the arrangement of the short circuiter ( 30 ) Fastening means ( 32 . 32 ' ) available. Circuit breaker according to one of the preceding claims, characterized in that the short circuiter ( 30 ) in an insertion shaft ( 14 . 14 ' ) is arranged. Circuit breaker according to claim 7, characterized in that in the insertion shaft ( 14 . 14 ' ) electrical contact means ( 24 ' . 24 '' ) are provided, which for receiving arranged on the short-circuiting electrical counter contact means ( 36 ' . 36 '' ) are suitable. Circuit breaker according to Claim 7 or 8, characterized in that the insertion shaft ( 14 . 14 ' ) is designed lockable. Circuit breaker according to claim 8, characterized in that via the contact means ( 24 ' . 24 '' ) electrical power and working variables between circuit breaker ( 10 ) and short circuiters ( 30 ) are transferable. Circuit breaker according to one of the preceding claims, characterized in that the circuit breaker a lock against the restart of the circuit breaker ( 10 ), which after triggering the switching function in the short circuiter ( 30 ) enters into function. Circuit breaker according to one of the preceding claims, characterized in that the detection unit ( 20 ) is an electronic detection unit. Circuit breaker according to one of the preceding claims, characterized in that the short circuiter ( 30 ) is associated with a detection unit for an arc fault.